Valve for operating automatic brakes



(No Model.) Y B/G. ROWELL & G. A-. AYER. VALVE FOR OPERATING AUTOMATIC BRAKES. 7

No. 534,244. Patented Feb. 12, 1895.

IIY a up Z nu: 'nonals virus 90., PifO'IO-LITHO. wasnmumu u c UNITED STATES BENTON C. RO WELL AND GEORGE A. AYER, OF BOSTON, MASSACHUSETTS,

PATENT OFFICE.

VALVE FOR OPERATING AUTOMATIC BRAKES.

SPECIFICATION forming part of Letters Patent No. 534,244, dated February 12 1895.

Application filed April 11, 1890.

To all whom it may concern:

Be it known that we, BENTON O. ROWELL and GEORGE A. AYER, of Boston, in the county of Suffolk and Commonwealth of Massachusetts, have invented certain new and useful Improvements in Valves for Operating Automatic Brakes, of which the following is a specification. Our improvements are especially applicable to valves used upon the pipes of airbrakes, which are automatically raised from their seats for the purpose of making a vent for the compressed air in the train pipe of an air brake apparatus, to set the brakes, and consist in providing the valve-chamber with an auxiliary air-chamber and extending the valve-stem into it, so that when the valve is opened for the purpose above mentioned, the extended valve-stem will act as a plunger in the air-chamber; also in providing the airchamber with an outlet near its inner end, and in applying to this outleta check or back-pressure valve which opens and remains so when the current of air is outward, but closes immediately when the current is inward, and further, in making a small vent opening into the air-chamber through which the air will enter slowly back of the plunger, and for convenience of regulating the flow of air through the vent, we control its size by means of a screw.

The object of our invention is to provide a valve to be used in connection with the pipes of a steam or air-brake, which may be automatically opened by a rod or lever attached to the frame of a car-truck or locomotive, and operated by proper devices placed beside the track for that purpose, and after the train has passed such operating devices, have the valve automatically close within a desired limit of time, and also provide an aircushion to relieve the shock incident to the violent and sudden opening of the valve.

In the drawings forming a part of this specification, Figure 1 is a side elevation of the frame of a locomotive pilot, showing the valve and rod by which it is opened, attached to the frame, and an inclined plate beside the track which operates the rod. Fig. 2 is an enlarged vertical sectional view of the valve. Fig. 3 is a cross-section of the valve on line w-w,

Serial No. 347,513- (No model.)

Fig. 2, viewed from above. Fig. 4 is a plan view of the devices shown in Fig. 1.

Similar letters in the drawings indicate the same parts of the devices.

A is the pilot frame; B the inclined plate beside the rail; 0, the valve-cylinder; c, the valve; D, the valve-stem d, the extended end of the valve-stem which works as a plunger in the auxiliary air-chamber e.

f, is the outlet provided with. a check or back-pressure valve, which, in the instance illustrated, consists of a small ball, I), placed within the outlet passage, the inner end of the passage being smaller than the diameter of the ball and having a counter-sunk seat for the ball, while the outer end of the passage is obstructed by a pin or any other obstruction to prevent the ball from rolling out when the air is forced outward by the entrance of the plunger d into the air-chamber, e, as the valve is opened.

We make the outlet, f, a little below the extreme inner end of the air-chamber, e, in order to leave a small space in which the air maybe compressed and serves as an air-cushion to relieve the shock liable to occur when the valve is suddenly and violently-forced open.

When the locomotive, or car, is passing the inclined plate, B, the friction wheel on the lower end of the rod, or valve-stem, D, will come in contact with the said plate and the valve-stem will be forced upward, thereby opening the valve. At the same time the extended end, d, of the-valve-stem will move into thechamber, e, the air readily escaping therefrom through the large outlet, f, until the end of the valve-stem has passed the upper limit of that outlet, when the air in that portion of the chamber will be somewhat compressed and serve as a cushion between the end of the chamber and the valve-stem. When the car has passed the inclined plate, B, the weight of the valve-stem and valve will tend to close the valve and as soon as the plunger begins to recede from the air-chamber, it will produce a current of air inward through the passage, f, and immediately draw the ball, b, inward to its seat and stop the flow of air in that direction, and unless other means of admitting air to the chamber, e,

were provided, it would be difiicult to withdraw the plunger therefrom, because of the tendency to produce a vacuum in the chamber thereby. Consequently, we makea small passage or vent-opening, g, into the air chamber at its inner end and regulate the size of this vent by a screw, h, and thus regulate the rapidity of movement of the plunger outward by the rapidity of ingress of air to the chamber, e, through the vent g.

If desired, the vent opening may be made through the upper side of the inner constricted portion of the passage, f, and controlled by a screw similar to h, through the top of the valve cylinder.

We claim In combination a valve chamber; a valve for controlling the flow of air or other fluid BENTON C. ROWELL. GEORGE A. AYER.

Witnesses:

JAMES C. OHADWIoK, J. M. PARKER. 

